The invention relates to a stretch wrapping operation in which the stretch wrap film is severed after a load is wrapped.
Stretch wrapping processes which are performed on a semiautomatic basis have required an operator to sever the film and secure the trailing end of the film onto the load after the sheet of film web has been wrapped around the load. This generally required the operator to dismount from a forklift truck to perform this operation manually and then remount the forklift truck to remove the load. In some instances, the operator would cut the film with a knife. In other instances, the operator would stick his or her finger through a portion of the film and grasp the film behind that portion to sever the film.
Automated attempts to sever the film have only been effective after the wrapping process has ended and the film is in a relatively stationary position. Such film cutting is typically accomplished with an exposed hot wire which is passed through the film web across its full width. The hot wire is located well outside the roll carriage which forms the stretch wrap dispenser. The exposed hot wire can be hazardous to a careless operator. Also, this approach leaves a very short tail of film web extending from the stretch wrap dispenser which may cause difficulties in having the operator grasp and pull the film web out of the stretch wrap dispenser and attach it to the next load for the next wrapping cycle.
Attempts have been made to snap the film by stopping the film drive motor. These attempts resulted in unreliable and unpredictable situations in which the film broke at undesirable or unpredictable locations within the stretch wrap dispenser, thereby requiring the film to be at least partially pre-threaded.